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Post by sean on Mar 5, 2009 23:29:56 GMT 10
I've just done some refurbishment work to my long-suffering Pike. For the last six months or so I've been flying it without a switch, the idea being there's one less component to fail. But... The standard JR-type battery plug was starting to show signs of wear and didn't look like it could be trusted. So I replaced it with a 4-pin Deans micro connector. This gives a degree of redundancy - the positive and negative have two pins each, and there are two leads going from the plug to the rx - one lead plugs into the battery socket as usual and the second lead plugs into a spare rx channel. That way if either lead fails there'll still be power to the rx. The Deans plugs are very sturdy and reliable, and with no switch this should make for a pretty dependable power connection. PS - I weighed the Pike and it came out at 2880g!! Crazy.  |
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Post by jirvin4505 on Mar 6, 2009 0:03:27 GMT 10
.... So I replaced it with a 4-pin Deans micro connector. ......... PS - I weighed the Pike and it came out at 2880g!! Crazy. Good move Sean. My first Europhia got damaged early in its life when the JR plug stopped working as a switch. I also know of 3 other models damaged in the same way. The standard servo plugs aren't designed for routine connecting and reconnecting. 2.88kg  It is surprising how well it launches at that weight. When i read on the German forums of my Europhia regularly flying on the slope at 3.4kg- we haven't seen heavy yet! cheers jeff |
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Post by sean on Mar 6, 2009 0:23:09 GMT 10
Wow, I didn't know that, even happier I've replaced them now!
It seems to launch very nicely in a headwind but in still air or a slight tailwind it gets pretty mushy on tow! Although last weekend I found myself pulling back on the elev during a launch in still air. Must have been subconcsiously trying to make it climb a little steeper. Soon as I realised what I was doing and kept the elev neutral my still-air launches got much better.
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Post by sean on Mar 6, 2009 0:30:05 GMT 10
One other thing - I have some lead directly in front of the battery to fine-tune the CG. It's made from several pieces of 1.5mm lead sheet double-sided taped together. It had become deformed from the battery repeatedly pounding into it presumably from all those dork landings. It's a good thing the battery pack is solidly built with a thick layer of insulation or it could have worn a hole in the insulation and shorted on the lead... I've since packed some foam-rubber inbetween the battery and lead.
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Post by nick on Mar 6, 2009 6:30:45 GMT 10
howdy sean
good job that lead looked very suss last sunday, i was surprised that you would risk such a nice plane and i wouldn't have liked to see it punch in, so are you saying that you can power up your plane useing any receiver port?
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Post by sean on Mar 6, 2009 8:41:42 GMT 10
Hey Nick, Yep, you can plug your battery into any receiver port and it'll do the job.
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Post by nick on Mar 6, 2009 9:18:57 GMT 10
cool thats a great saftey you have there  |
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Post by sean on Mar 6, 2009 9:34:36 GMT 10
There's some really good info on redundant power supplies here: www.hangtimes.com/rcbattery_faq.htmlThe ultimate is two packs, each with its own switch plugged into a separate rx socket. Scroll down to "Parallel / Redundant Battery Packs" (about halfway down). |
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Post by nick on Mar 6, 2009 17:04:14 GMT 10
thanks sean
that is a very interesting page, heaps of useful info,
see you saturday
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Post by bananaman on May 28, 2009 17:56:48 GMT 10
Certainly a good idea, I've been using a small toggle switch but my last two prangs have had me scratching my head, regarding the suitability of my power supply. So I've added even more redundancy. My packs are now made up of double wires between cells, I've used the next gauge up from heavy duty servo wire. I'll discard the switch as you have done but use a Multiplex connection, 3 connections per wire plus its bigger for my gorilla fingers. I've added a separate JR pigtail lead so I can charge each pack.
I destroyed a Victor F3b to genuine JR battery connector pin pushing out when I plugged it in after a charge. Everything worked on the ground until halfway through the launch when the electrons ceased flowing.
Good to see you have good insulation in there too.
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Post by skyboyken on May 28, 2009 22:21:59 GMT 10
FWIW I recommend an LED battery monitor on any plane you care about. We don't have room for redundant packs but these can always be fitted in.
They are available very cheap at Hobbycity. I have one in my Caracho and it has saved the plane at least once. I have a different one in the X pro and it also works well and gives me better peace of mind.
At the Armidale comp in January I turned the plane on while watching the monitor's LEDs and noticed there was a delay between activating the switch and the LED lighting up. So I put the plane away and flew the X Pro for the rest of the comp.
Back at home I checked the wiring harness and discovered a broken solder joint at the switch, which was capable of going open circuit at any time.
So I heartily recommend this simple piece of safety equipment.
The other thing I recommend is to use a good battery charger for your Rx and Tx packs - one with at least a mAH readout. I do 3 cycles on a new Rx or Tx pack, and note the mAH reading from the last charge. I replace the pack when the capacity has dropped to about 90% or immediately if it drops suddenly. I also cycle the Rx pack from time to time to exercise it and to check capacity, so a cycling charger is good too.
Another thing you can do is make a practice of giving your expensive models a Christmas present every year - of a new Rx pack. That's what we used to do in the good old days of Nicads and it is still cheap insurance - after all a cell can fail at any time, and insulation can wear through.
Finally, there's nothing sadder than standing over the wreckage of your beautiful plane thinking 'if only I'd...'
Ken.
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It is surprising how well it launches at that weight.
